三种准分子激光角膜切削术后中央角膜厚度变化的对比研究

Comparison of Corneal Thickness after Three Kinds of Excimer Laser Refractive Procedures

目的比较三种准分子激光角膜切削术后中央角膜厚度(CCT)的差异并探讨不同手术方式角膜切削量的设定。方法使用Pentacam三维眼前段分析仪测量行SBK、LASIK、Epi-LASIK术的近视患者共136例266只眼术前术后的CCT,按屈光度分为低、中、高三组,分别计算和比较CCT及实际切削深度和设计切削深度的差值(Diff值)。结果Epi-LASIK患者低、中、高度组术前CCT分别为(495.70±24.94)、(501.57±31.34)和(525.18±16.53)μm,较SBK和LASIK组患者CCT明显偏薄(P<0.01),SBK与LASIK患者术前术后的CCT无显著性差异。SBK、LASIK术后Diff值比较:低度组Diff值分别为(6.57±12.72)、(5.33±9.51)μm;中度组Diff值分别为(7.07±18.19)、(4.42±8.72)μm;高度组分别为Diff值(11.52±10.29)、(7.00±7.33)μm,各组比较差异均无显著性意义。三种手术方式的实际切削的角膜深度均大于设计量。结论CCT较薄的患者多选择Epi-LASIK。充分估计术中实际切削深度与设计切削深度存在的差异是提高手术安全性的保障。

Objective To investigate the changes in central corneal thickness （CCT） before and after different excimer laser refractive procedures and the settings of ablation depth before them.Methods Pre-and post-operation CCT in 266 eyes of 136 myopic patients who proceeded SBK,LASIK and Epi-LASIK was measured by Pentacam.All cases were divided into low,moderate and high groups according the diopter of myopia to compare the changes in CCT and difference of measured and estimated ablation depth.ResultsThe pre-operation CCT of low,moderate and high groups with Epi-LASIK was （495.70±24.94）μm,（501.57±31.34）μm,and （525.18±16.53）μm,respectively,thinner than the other two groups significantly（P0.01）.After SBK and LASIK,Diff value was （ 6.57±12.72）μm and （5.33±9.51） μm in low myopia ones,（7.07±18.19） μm and （4.42±8.72） μm in moderate myopia ones and （11.52±10.29） μm and （7.00±7.33） μm in high myopia ones,there was no significant difference.The measured ablation depth all exceeded the estimated one in three kinds of operations.ConclusionsPeople who have thinner CCT always choose Epi-LASIK.Consideriing the discrepancy of measured ablation depth and estimated one sufficiently is the guarantee of operation safety.